Open water performance comparison between hub-type and hubless rim driven thrusters based on CFD method

The rim driven thrusters (RDT) have been designed both in hub-type and hubless type, but few comparison studies have been performed. This paper investigates the difference between open water performance of hub-type and hubless RDT by means of computational fluid dynamics (CFD) analysis. The Reynolds Averaged Navier-Stokes (RANS) equations were numerically solved by the commercial code CFX 14.0 with a multiple frames of reference (MFR) method. The accuracy of the numerical method was validated through verification and validation studies. Four pairs of hub-type and hubless rim driven thrusters having different hub radius were tested. The simulation results demonstrate that the hubless RDT efficiency is higher than that of the hub-type RDT. The hubless RDT also has a larger thrust, torque and a smaller thrust ratio. The reasons for the difference were also discussed in the present paper. The flow field details were also presented.